Files
linux/drivers
Ding Hui 5b66b27b9d efi: fix userspace infinite retry read efivars after EFI runtime services page fault
commit e006ac3003 upstream.

After [1][2], if we catch exceptions due to EFI runtime service, we will
clear EFI_RUNTIME_SERVICES bit to disable EFI runtime service, then the
subsequent routine which invoke the EFI runtime service should fail.

But the userspace cat efivars through /sys/firmware/efi/efivars/ will stuck
and infinite loop calling read() due to efivarfs_file_read() return -EINTR.

The -EINTR is converted from EFI_ABORTED by efi_status_to_err(), and is
an improper return value in this situation, so let virt_efi_xxx() return
EFI_DEVICE_ERROR and converted to -EIO to invoker.

Cc: <stable@vger.kernel.org>
Fixes: 3425d934fc ("efi/x86: Handle page faults occurring while running EFI runtime services")
Fixes: 23715a26c8 ("arm64: efi: Recover from synchronous exceptions occurring in firmware")
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 11:58:10 +01:00
..
2023-01-07 11:11:39 +01:00
2022-12-31 13:33:12 +01:00
2022-12-31 13:32:09 +01:00